Question

The length of AB is __

Answer 1

Answer:

The length of arc AB = 10.99 inch.

Step-by-step explanation:

We know that,

The length of any arc of a circle = Radius of circle $\times$ Angle subtended by              arc at centre of circle.

According to the figure,

Angle subtended by arc at centre,$\alpha$ = $\frac{\pi }{2}$

Radius of the circle, $R$ = 7 inch.

The length of arc AB = $R\times\alpha$

                                   = $7\times\frac{\pi }{2}$

                                   = 10.99 inch.

Answer 2

Answer:

AB = 3.5π

Step-by-step explanation:

The length of arc AB is calculated as

AB = circumference of circle × fraction of circle

     = 2πr × $\frac{90}{360}$ ( r is the radius and r = 7 )

     = 2π × 7 × $\frac{1}{4}$

     = $\frac{14\pi }{4}$ = 3.5π